1. Field of the Invention
The present invention relates generally to the banding of bales formed by a hay baler with a tying medium, such as wire or the like, and, more particularly, is concerned with an improved assembly for guiding the tying medium toward the tying mechanism of the baler.
2. Description of the Prior Art
Heretofore, assemblies of rollers and guides have been provided on a hay baler, being mounted on the bottom of the bale case thereof, for guiding a tying medium, such as usually two or three strands of wire or the like, from a source of supply thereof, such as spools of wire mounted on the baler adjacent the bale case, toward tying means on the baler, such as usually two or three wire tying or twisting mechanisms.
The prime requisites of satisfactory roller and guide assemblies include the combined ability of the rollers and guides to positively guide or control the path of movement of the wire, low inertia and bearing drag characteristics on the part of the rollers, an adequate roller diameter to minimize wire drag thereon, the relative ease of threading of the wire strands through the guides and superior durability of the parts which promotes prolonged life and postpones repair or replacement.
One recent version of the roller and guide assemblies utilizes a standard ball bearing chain idler-type roller and slotted guide plates, such as illustrated in FIGS. 7 through 9. These components have performed satisfactorily at lower baling speeds. However, with the advent of higher baling speeds in which the wire strands must be pulled from the supply source with greater velocity, the drag and inertia characteristics of the conventional chain idler-type rollers has become more critical as evidenced by reduced component life and typing problems due to increased component wear. The difficulty to be overcome is that the heavy construction of these chain idler-type rollers, which is necessary to maintain an adequate life span for the rollers due to their contact with highly abrasive wire, creates high inertia forces and generally has higher bearing drag. Further, the slotted guide plates tend to guide the wire to one location on the roller thereby creating a concentrated wear pattern which ultimately shortens the useful life of the roller. Also, the slots of the guide plates are defined by sheared edges which commonly contain burrs which contact the wire and increase the inertia forces and drag thereon.